The field of the present invention is pumps with heat exchangers.
In pumps used in connection with hot liquids, such as reactor cooling water, it is often advantageous or necessary to cool the pump, or pump components such as mechanical seals. To this end, heat exchangers may be provided with the pump to provide a cooling function.
For example, U.S. Pat. No. 3,478,689 discloses a high-pressure, high temperature reactor circulating pump having a thermal plate and a heat exchanger shield for cooling a shaft seal. In addition, U.S. Pat. No. 3,459,430 discloses a mechanical seal assembly having cooling coils within a cooling jacket. A recirculation impeller driven by the pump shaft causes liquid to flow over the heat dissipating surfaces of a mechanical seal cartridge and a radial bearing, to cool these components. The heat absorbed in the liquid is dissipated from the cooling coil into a liquid that flows over and around the coil.
An improved heat exchanger is described in U.S. Pat. No. 4,005,747 for use with a pump assembly incorporating mechanical seals, such that the seals are cooled not only during pump operation, but also in the hot-stand-by condition. This heat exchanger is constructed with a rotating baffle which defines the path of hot fluid flow and which when rotating, causes rotational motion in the hot fluid. The heat exchanger is designed so that the coolant flows in a defined path along the pump shaft to the mechanical seals.
Although these known cooling techniques have performed well in the past, a further improvement in the cooling of the mechanical seals would prolong their useful life and improve reliability.